Appropriate questions should concern specialist knowledge: the meaning of a statement, context, form of expression, presence of statements of fact, value judgements, negative information, or signs of a threat or incitement.
Questions of guilt, legality and liability are best kept outside the questions put to a linguist.
What you can do
- collect the disputed text and its context;
- formulate appropriate questions for a specialist;
- assess whether a combined examination is needed;
- prepare a specialist opinion or an expert report review.